JPH086408Y2 - Downward speed control device for ground work machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a device for controlling the descending speed of a ground work machine such as a rotary tiller connected to a tractor, and lowering a hoisted ground work machine to lower the ground work machine. The present invention relates to so-called de-sera control in which the descending speed is decelerated when the distance approaches.

[Prior Art] Conventionally, examples of devices of this type include those described in JP-A-56-92702 and JP-A-60-192501.

[Problems to be solved by the invention] However, the former device merely detects a change in the plowing depth sensor to decelerate the descent speed, and the ground work machine descends from the air to reach near the ground. Since the descending speed is high up to and it descends slowly after entering the ground, there is a drawback that the moving speed is too slow on both the ascending side and the descending side during automatic plowing depth control, resulting in poor responsiveness. is there.

Also, the latter device is a slow descent for a fixed time when the working machine is lowered, and thereafter is for rapid control, so the descent speed changes depending on the weight of the working machine,
Therefore, there is a problem that the points at which the speed changes are not constant.

[Means for Solving Problems] The present invention is proposed in view of the problems described above, and slows down the descending speed only when lowering the ground work implement that has been hoisted to the vicinity of the upper limit of ascent, and The purpose of this is to improve the efficiency of the work by softening the impact so that the moving speed does not slow down on the ascending side and the descending side during the automatic plowing depth control.

 Therefore, the following technical measures were taken.

That is, a plowing depth sensor for detecting the plowing depth of a ground working machine provided by a hydraulic raising / lowering mechanism, a plowing depth setting device for setting the plowing depth, and raising / lowering operations according to the difference between the two values are performed. In addition to having a control unit that raises and lowers the hydraulic lifting mechanism to control the working depth, a lift arm angle sensor that detects the rotational position of the lift arm that constitutes the hydraulic lifting mechanism is connected to this control unit, When the lift arm angle sensor detects that the lift arm descends from the raised position and reaches a predetermined point near the ground, the descending speed is decelerated to ground the ground work machine. In the descending speed control device for the ground work machine, the deceleration of this descending speed is performed only after the position of the ground work machine is raised by the position lever or the elevating switch to raise the lift arm to a position near the upper limit. A control means is provided which is performed only when the ground work implement is lowered, and the deceleration control is not performed even if the lift arm passes through the predetermined point and descends again during the working depth control. The construction of the descending speed control device of the ground work machine is as follows.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, a ground work machine 2 such as a rotary tiller is mounted on the rear part of the tractor 1 to a pair of left and right lift arms 3 and 3 by swinging it up and down via left and right lift rods 4 and 4. The working machine connecting link 7 is composed of the lower links 5 and 5 and the central top link 6, and the working machine connecting link 7 lifts and lowers the lift arms 3 and 3 by a lift cylinder 8 using hydraulic pressure. The hydraulic lifting mechanism 9 for rotating is configured to move up and down.

In addition, in order to control the supply and discharge of the pressure oil to and from the lift cylinder 8, the operation command of the control unit 11 composed of a microcomputer or the like is accompanied by the operation of the elevating switch 10 provided on the instrument panel. 12 or the lowering drive unit 13 is amplified to open / close the proportional solenoid valve 14 for elevation or the proportional solenoid valve 15 for lowering, whereby the pressure oil of the pump 16 is supplied to the lift cylinder 8 and the lift arm 3 3 is moved up, or the pressure oil of the lift cylinder 8 is discharged, and the lift arms 3 are moved down.

Furthermore, the position lever I ₁ provided near the cockpit and the detection axis of the rotary potentiometer are connected to the lift arm 3.
The lift arm angle sensor S ₁ formed by being connected to the control unit 11 is connected to the control unit 11 to detect the height detected by the lift arm angle sensor S ₁ at the set value set by the operation of the position lever I _1. The control unit 11 outputs an elevating command to the ascending drive unit 12 or the descending drive unit 13 so that the values match, and thereby position control is performed.

Further, for automatic tilling depth control, the tilling depth sensor S ₂ of the ground work implement ₂ detects the tilling depth setting value set by the operator using the tiller depth setting device I _{2 including} a volume control. The solenoid valve 14 for raising or the solenoid valve 15 for lowering is energized until the working depth detection values match, and these solenoid valves proportionally control the opening area of the flow passage of the pressure oil in proportion to the amount of current applied to the solenoid. A solenoid valve is used, and a control current of a magnitude proportional to the difference between the plowing depth set value and the plowing depth detection value is output from the control unit 11, and a pulse current having a pulse width proportional to the control current value is output from the solenoid valve. In addition, the ground work machine 2 can be moved up and down.

Further, the tilling depth sensor S ₂ of the illustrated example is one in which the movement of the rear cover 17 whose lower end is in sliding contact with the surface of the cultivated soil is detected by a linear movement type potentiometer 18, and is provided to the rear part of the ground work machine 2. The rear cover 17, which is pivotally rotatable up and down, is held at a constant height by the lifting rod 19 in the hoisting posture in which no cultivating work is performed. As the machine 2 descends, it moves upward when it touches the ground, and the pot depth corresponding to this turning position is detected by the potentiometer 18.

Also, as described above, the tractor 1 of the lift arm 3
A rotary potentiometer is used to detect the rotation angle with respect to, and after the ground work implement 2 is raised, it is lowered and the descent speed is rapidly reduced immediately before touching the ground, resulting in a very gentle movement. A descending speed deceleration control (desera control) is employed in which the vehicle is grounded to reach a certain depth and then the normal automatic plowing depth control is performed.

Such de-sera control has been conventionally performed, and is generally performed by inserting a throttle valve into an oil passage for returning the pressure oil in the lift cylinder 8 into the tank, but it should not be limited to this method.

Thus, when the ground working machine 2 such as the rotary tilling device towed by the tractor 1 having such an electrohydraulic mechanism is operated by the plowing depth control and the de-sera control to perform the rotary tilling work, When the position lever I ₁ or the elevating switch 10 is operated to the up side to raise the lift arm 3 by about 60 degrees or more above the position substantially parallel to the ground surface (see FIG. 3), that is, the lift arm 3 is raised. The lift arm 3 is moved up by operating the position lever I ₁ or the elevating switch 10 within a range of about 5 ° below the upper limit of 65 °, and is lowered from the raised position by the position lever I ₁ or the elevating switch 10. Only when the ground work machine 2 is grounded, the descending speed is rapidly reduced immediately before the ground work machine 2 comes into contact with the ground, and the ground work machine 2 descends very gently. Of.

Even if the lift arm 3 moves up to the vicinity of the upper limit position, if the lifting operation is based on the automatic plowing depth control, the desera control is not performed. In other words, in the entire operable range of the lift arm 3, the rising speed,
Lift arm 3 without any restrictions on the descending speed
Moves up and down quickly.

Further, when the lift arm 3 is raised by operating the position lever I ₁ or the raising / lowering switch 10, if the rise does not rise to a predetermined range near the upper limit of the rise, the de-sera control is not performed. .

That is, when the lift arm 3 is raised to the vicinity of the upper limit of the elevation based on the automatic control, and is lowered from this position to contact the ground, the de-sera control does not operate, and the deceleration is lowered to a predetermined depth of the cultivated soil at a normal speed. Furthermore, position lever I
_{Even in the case of one} operation, up to near the above upper limit,
That is, the limit of the rising angle from a position substantially parallel to the ground surface is 65
In terms of degrees, it does not rise to a position of about 5 degrees below the upper limit angle of 65 degrees, but when it is lowered from this position, it is lowered to a predetermined depth of cultivated soil at a normal lowering speed. That is, since the de-sera control is supposed to work only when the lift lever 3 is lowered from the vicinity of the upper limit by the position lever I ₁ or the elevating switch 10, the ground working machine 2 such as a ridge is not lifted greatly. When the machine body is turned by, the de-sera control does not work, so that the original plowing depth can be restored in a short time, and the rotary plowing work by the automatic plowing depth control can be performed extremely efficiently.

[Advantage of the Invention] As described above, the present invention has a tilling depth sensor for detecting the tilling depth of a ground working machine provided by a hydraulic lifting mechanism, a tilling depth setting device for setting the tilling depth, and A control unit for raising and lowering the hydraulic lifting mechanism to control the working depth so as to perform a lifting operation according to the difference between the two values is provided, and this control unit detects the rotational position of the lift arm that constitutes the hydraulic lifting mechanism. When the lift arm angle sensor detects that the lift arm angle sensor is connected, and the lift arm descends from the raised position and reaches a predetermined point near the ground, the descending speed is decelerated to ground. In the descending speed control device for a ground work machine configured to ground the work machine, the deceleration of this descending speed causes the ground work machine to raise the lift arm to a position near the upper limit by a position lever or an elevating switch. After being lifted, it is performed only when the ground work implement is lowered from that position, and the deceleration control is not performed even if the lift arm passes through the predetermined point and lowers again during the working depth control. Since the control means is provided, the derailleur control does not operate when the lift arm is raised during the automatic plowing control and turns to the descending side. The response is quick and the rotary tillage work is well performed without being affected by the desera control.

Then, only when the operator artificially operates the position lever or the elevating switch to raise the lift arm near the upper limit, when the lift arm descends from this position and reaches a predetermined point near the ground, Since the de-sera control operates, problems such as a heavy impact on the tractor main body side when the ground work implement lands and a dangerous state due to dashing of the fuselage are eliminated.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a control circuit diagram, FIG. 2 is a side view of a tractor, and FIG. 3 is an explanatory view showing a rotation angle of a lift arm. Explanation of code 1 …… Tractor 2 …… Ground work machine 3 …… Lift arm 4 …… Lift rod 7 …… Work machine connection link 9 …… Hydraulic lifting mechanism 10 …… Lift switch 11 …… Control unit I ₁ …… Position lever I ₂ …… Plowing depth setting device S ₁ …… Lift arm angle sensor S ₂ …… Plowing depth sensor

Claims (1)

[Scope of utility model registration request] 1. A tillage depth sensor for detecting the tilling depth of a ground working machine, which is provided so as to be able to be raised and lowered by a hydraulic lifting mechanism, a tilling depth setting device for setting the tilling depth, and raising and lowering according to the difference between the two values. A lift arm angle sensor for detecting the rotational position of the lift arm that constitutes the hydraulic lifting mechanism is provided in addition to the control unit that controls the working depth by raising and lowering the hydraulic lifting mechanism to perform the operation. When the lift arm angle sensor detects that the lift arm rotates downward from the raised position and reaches a predetermined point near the ground, the lowering speed is reduced to ground the ground work machine. In the descending speed control device for a ground work machine configured as described above, the deceleration of the descending speed is performed after the ground work machine is raised by the position lever or the elevating switch to raise the lift arm to a position near the upper limit. The control means is provided only when the ground work implement is lowered from the set position, and the deceleration control is not performed even when the lift arm passes through the predetermined point and descends again during the working depth control. A descending speed control device for a ground work machine characterized by.